How to avoid sales tax in Ohio

[rdemattio]

Alright fellas, hope you can help! I am purchasing a 2008 Mazda 3 here in Texas for 8,500$. When i get back to Ohio they are going to tax me on $8500. Can the seller write that I bought car car for, say, $3,000? To save on sales tax? Or would that be like fishy? lol. Please help, I'm trying to save some money =]